This invention relates to multi-layered sheet materials used in making, e.g., foam products.
In making foam automobile seat cushions, for example, a multi-layered sheet is bonded to a finish fabric. The finish fabric is then cut and sewn to form a seat cushion cover for encasing a foamed-in-place pad. Prior to forming the foam pad, the outer layer of the multi-layered sheet is peeled away, exposing an inner film layer. A foaming liquid is then injected into a mold lying adjacent the exposed inner layer. The foam fills the mold and bonds to the film layer to form the foam pad.
One such multi-layered sheet, produced by Atochem in Germany, is manufactured by co-blown extrusion of urethane and polyethylene layers. The urethane and polyethylene layers are extruded through concentric circular dies to produce two cylindrical layers which exit the dies in an upward direction. At a point above where they exit the dies, the two layers are pressed together with nip rolls and flattened into four layers. The edges are split and the four layers are separated into two multi-layer sheets.